Yes, I did post sometime back about fixing slop in a worn trans cover with roll pin sections. It's a little tedious - buy good files.

Keep in mind that you are trying to re-center the slot position, as it has been "moved" by the wear that's caused the slop.

The "ball" wants to be centered on the cup and in contact, via grease. So not only do you have to carefully file the slots wider - they also have to be deeper by the thickness of the roll pin, to re-establish the correct location of the two parts to one another.

You want the roll pin pieces to be as long as possible, but not so long that they protrude into the threads of the cap. Put the split facing up, obviously.

I centered and widened the slots with flat files and then worked on the depth with rat tail files. As it "drops" down into the cup, it becomes apparent how "uncentered" it is, and so you correct - file the opposite side of the slot to where the ball is contacting the cup. It was a matter of filing and fitting, filing and fitting. Also, I didn't replicate the beveled corners in the bottom of the slot - I went with rounded.

I may wrong about this, as I'm sure whether the pins rest up from the bottom of the slot or not (in neutral)

Maybe this is something a machine shop could do for not too much money.